Spring hammer



E. ROUCKA ET AL July 10, 1951 SPRING HAMMER Filed Sept. 21, 1949 Patented July 10, 1951 TENT OFFICE SPRING HAMMER Erich Rouka and Frantisk Streit, Brunn,

' Czechoslovakia Application September 21 In Czechoslovakia 3 Claims. 1

Spring hammers are already known, in which the strikin force is regulated, with a continuously running drive, by altering the stroke imparted to the spring member of the hammer by means of an adjustable rod and lever mechanism; but known arrangement of this type suffer from many disadvantages. Insofar as slide controls are used, these are comparatively heavy, and as the sliding block is continually undergoing displacements in the slot guide even with a constant stroke, uneven wear of the rubbing surfaces of the guide is liable to occur, resulting in considerable losses of energy through friction.

The present invention obviates these disadvantages through a new formation of the transmission rodwork designed for altering the stroke. The invention consists primarily in the feature that the hammer drive sets a suspension member in constant oscillation about an axis, this sus-' pension member being pivotally connected with a link, which is attached at one end to the connecting rod of the drive for the spring member of the hammer and at the other end to a connecting-rod which is pivoted to an adjusting member influenced by the hammer control.

One form of construction of the invention is diagrammatically illustrated in the accompanying drawings, in which:

Figure 1 represents the arrangement as a whole; and

Figure 2 is a view of a detail at A in Figure 1 as seen from the right.

The numeral I denotes the spring beam, which can swing or. oscillate about the fixed pivot 2, i

and which is connected at one end to the hammer tup 3 and at the other end to a connectingrod 4. This connecting-rod is pivotally connected with a link 5, the other end of which is connected on the one hand to a suspension member l6, and on the other hand to a connectingrod H actuated by a crank l2, which is driven by a motor l by means of a belt l4 and a pulley l3. The suspension member I6 can rock about a fixed pivot at 28. From the joint connecting the connecting-rod 4 with the link 5 a rod 6 leads to an adjusting member in the form of a cross-head 1, which slides in a fixed guide 29. The cross-head 1 is connected with the piston 9 of a hydraulic cylinder l 0 by means of a piston rod 8. This hydraulic servo-motor, the functioning of which does not concern the present invention, will be described only in a general way. It is provided with a control valve [8 in a valve casing H, with an inlet pipe [9 for the 1949, Serial No. 117,045 October 22, 1948 pressure medium, with a non-return valve 20, a storage reservoir 2| for the working fluid, a pump 22 and an air vessel 30. The control valve l8 is linked by means of a connecting-rod 23 to a compensating lever 24, which is pivoted at one end to the cross-head 1 and at the other end to a connecting-rod 25, which is connected by means of the lever 26 with a controlling pedal 21.

The suspension member I6 is made in the form of a crank which is rotatable in stationary bearings 28. On its crank pin jointly engage the link 5, which is preferably duplicated, as shown in Figure 2, and the connecting-rod Il,'whilst at the other end of the pair of links 5, upon a common pin, are connected the connecting-rod 4 and the rod 6. The length of the suspension member [6 is equal to the length of the pair of links 5.

The arrangement functions in the manner now to be described.

When the motor I5 i running, a swinging movement of constant amplitude about the fixed pin at 23 is imparted to the suspension member I 5. As soon as the cross-head 1 is held in a stationary position by means of the servomotor 9, ID, the connecting-rod 6 undergoes a swinging movement about the pin of the cross head, since it is coupled by means of the links 5 with the suspension member It. In this manner the connecting-rod 4 also receives a certain stroke, which is transmitted to the spring beam l and brings about the hammerin action of the tup 3. If through a movement of the control pedal 2! a change of position of the crosshead I in the guide 29 is brought about by means of the servo-motor 9, Ill, (the work of the servomotor will not be described in greater detail here as it does not directly concern the present invention, and as it could be replaced by each other displacement of the sliding part 1), the swinging movement of the left-hand end of the connecting-rod 6 is also changed thereby, and therefore also the stroke of the spring beam I. This stroke reaches its maximum when the crosshead 1 is at the extreme left-hand position, and reaches zero when the left-hand end of the rod 6 assumes that position in which the axis of its joint coincides with the axis of the pin of the suspension member at 28. In this case the suspension member l6 swings with the links 5 about a common axis, and the connecting-rod 4 remains at rest.

It can be seen that on adjustable member I the adjustment of the to any desired constant 3 stroke, only rotary movements ensue in the joints, which ensures on the one hand minimum frictional losses, and on the other hand minimum and at the same time uniform wear. All continual sliding of the cross-head in its guides, which produces uneven wear and increases loss of energy in the known constructions is obviated. The rodwork may be comparatively light and very cheap in construction.

The adjusting member I may be moved by any suitable servo-motor, or by means of a mechanical transmission of known type so long as these fulfill the requirement that the forces occurring in operation and re-acting upon the adjusting member 1 are not transmitted to the control member 21.

The formation of the suspension member according to Figure 2 offers the advantage of a simple, strong construction, and affords the possibility of bringing the spring beam l completely to a standstill with the drive still running. Change of stroke can easily be carried out without the necessity of moving heavy parts.

We claim:

1. A spring hammer, comprising: a stationary fulcrum, a spring beam rockably mounted on the said fulcrum, a tup carried by one end of the spring beam, a first connecting-rod pivotally connected by one end to the other end of the spring beam, a link pivotally connected by one end to the other end of the first connecting-rod, a second connectingod pivotally connected by one end to the other end of the said link, powerdriven means for reciprocating the second con-. necting-rod, a suspension member adapted to end about a stationary axis, the other end of the suspension member being pivotally connected to the joint between the link and the second connecting-rod, a reciprocable member such as a crosshead, means for guiding the reciprocable member in a substantially rectilinear swing by one .path, a third connecting-rod pivotally connected at one end with the reciprocable member and at the other end with the joint between the first con-- necting-rod and the link, and means for adjusting at will the position of the reciprocable member in its guiding means.

2. A spring hammer as claimed in claim 1, wherein the link connecting the first connectingrod with the second connecting-rod is of the same length as the suspension member connected to the said link and to the second connecting-rod.

3. A spring hammer, comprising: a stationary fulcrum, a spring beam rockably mounted on the said fulcrum, a tup carried by one end of the spring beam, a first connecting-rod pivotally connected by one end to the other end of the spring beam, a duplicate'link consisting of two parallel plates connected by one end to the other end of the first connecting-rod, a second connecting-rod pivotally connected by one end to the other end of the said link, power-driven means for reciprocating the second connectingrod, a suspension member consisting of two par allel crank arms adapted to swing by one end about a stationary axis and a crank pin uniting the free ends of the two crank arms, this crank pin constituting the pivotal connection between the second connecting-rod and the link, a reciprocable member such as a cross-head, means for guiding the reciprocable member in a substantially rectinlinear path, a third connecting-rod pivotally connected at one end with the reciprocable member, a pin joint pivotally connecting the other end of the third connecting-rod with the first connecting-rod and with the duplicate link, and means for adjusting at will the position of the reciprocable member in its guiding 7 means.

ERICH ROUCKA.

FRANTISEK s'ranrr.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

